samantha mohr is tracking this cold front. some folks are having fun with it, this is painful. >> it could be painful. you were talking about frostbite, it can happen in minutes. we need to take it seriously. if you get stranded in this, it could be deadly. arctic air like we haven't seen in decades will be settling in here. you can also see low pressure is going to be heading up, intersecting the cold air. we have moisture and cold air at the surface, wintry mix, some heavy snow potentially on the back side of this system. so of course, that means we're going to see snow moving in, and that means delays. let's look at the current situation here. we have had over 900 flights cancelled in and out of the u.s. about 160 or so plus in and out of chicago o'hare so far today. you can see this is the flight explorer, shows where the planes are now. not as many in the air today as there would be, due to this inclement weather situation. then as we head into sunday, through the afternoon, overnight and into tomorrow, we will see snow m

samantha mohr is tracking the weather. is it true? boston will be hit again? >> oh, yeah. definitely will be hit again. the brunt of the throw or the punch since you called it a one-two punch, it will be throughout the mid nation. there was the first punch here. the second punch on its way in and final we've been watching for the snow to move into chicago. it is indeed moving in right now. o'hare just reporting light snow. so just the outer edge of the snow. but it's going to turn into much heavier snow as we head into the overnight hours and through sunday as well. winter storm warning in effect for chicago through tomorrow evening. all the areas you see draped here in pink and that lavender color, that means winter weather. gusting winds, blowing snow, incredibly cold temperatures once the arctic air moves in behind the low itself. it's all about timing. it's all about timing the moisture with the cold air and exactly when the two will meet will determine how much snow you get and how heavy that snow will be. so we'll be watching that carefully as the low moves on up fro